How much do you know about bearing unit of Pillow Block


Basic Introduction

Pillow block consists of Plummer Block (Bearing Housing) & Insert Bearing(Y-Bearing).It provides supports for a rotating shaft with the help of compatible bearings & other accessories.

The units are available in a variety of pillow block, flange, cartridge and take-up mounted configurations with one piece cast iron, ductile iron, stainless steel, thermoplastic or two pressed steel housings. There are many different combinations of insert bearings and housings.

Material of bearing units

A, Material of bearings:

The materials of the race and ball of bearing require enough hardness and the following qualities:
(1). Large fatigue strength against repeated stress due to fatigue fracture of the race surface which governs the life of the bearings.
(2). High limit of elasticity and high yield strength to prevent deformation when a large load is applied per unit area.
(3). Large abrasion resistance against sliding friction between the retainer and the ball.
(4). High strength against crack due to impact load and failure caused by improper fitting etc.
(5).Small secular change in dimension and shape due to change of structure or internal stress.

GCr15 Steel (High carbon chromium bearing steel) satisfies the above comparatively well, and its chemical composition is shown in the following table.

Chemical composition of high carbon chromium bearing steel

B, Material of housing:

Plummer Block Material included :
Cast Steel eg. ZG35, ZG45 / Grey Cast Iron eg. HT200, HT250 / Ductile Iron: QT400, QT450 /
Stainless: SUS304 / Plastic / Zinc Alloy

The most popular material of the housings is FC200 (Gray iron casting) and the mechanical properties are shown in the following table.

Mechanical properties of Gray cast iron HT200

C, Materials of Other Components


The reliability, simplicity and ease of assembly of items in the TBB ball bearing units range has resulted in their popularity for agricultural, extraction machinery, textile machinery, parking equipment, fan equipment and construction machinery as well as process and automation equipment.

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